Internal-combustion engine



n 1 12' 1624404 Apnl 2 9 7 F. w. FRESE INTERNAL COMBUSTION ENGINE Filed March 2.. 192,5. 2 sheets-sheet;- 1

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April '12, 1927. 1,624,404

' F. W. FRESE INTERNAL coNBUsToN ENGINE Fivled March 2. 1925 2 sheets-Shet 2 r .r1 111,114 m,

Patented Apr. l2, 1927.

UNITED STATES l FREDRICK W. FRESE, OF SPOKANE, WASHINGTON.

INTERNAL-COMBUSTION ENGINE.

Application filed March 2, 1925. SeralNo. 12,582.

' The present invention relates to improvements in internal combustion engines of the multiple piston type wherein two working -pistons move simultaneously in opposite directions in a single cylinder or cylindrical structure composed of two working cylinders arranged tandem with a combustion chamber or space between the pistons.

` The gases resulting from combustion of :the liquid fuel within the combustion chamber as they expand act with equal pressure upon .both pistons and transmit power through the pistons to the main driving or crank shaft of the engine or motor. The invention comprises a plurality of units as above indicated arranged in parallelism, and in the drawings I have illustrated a four cylinderunit in a motor, as an exemplification of my invention.

. By the utilization of my inventionV in an internal combustion engine a maximum of power is derivedfrom the use of a minimum quantity of fuel thus economizing in fuel consumption and enhancing the power of the motor.

lVhile the motor may be utilized in horizontal or other positions, I have shown it in vertical position for convenience of illustration and description.

The invention consists in certain novel ycombinations and arrangements of parts as will hereinafter be more fully set forth and claimed.r

In the accompanying drawings I have illustrated one complete example of the ,physical embodiment of my invention wherein the parts are combined and arranged in accordance with .the best mode I havev thus far devised for the practical application of the principles of. my invention.

Figure 1 is a vertical longitudinal sectional view showinga 'four cylinderengine embodying the principles Iof my invention,

the pairs of pistons in tli'e four cylinders" ranged in axial ahnement.

showing the four different relations of a single pair of pistons in a single piston.

Figure 2 is a Yhorizontal transverse sectional detail view showing a portion of the motor with exhaust and intake manifolds jconnected to .the cylinders;

'Figure 3 is' an enlarged detail sectional view at right angles to Figure 1 and at kline 3 3 of Figure 1.

Figure 4 is an enlarged detail sectional A. View of one of the. valve-pistons showing in Figure 1.

also'its connecting' rod and cam shaft in the form of a crank shaft.

Figure 5 is a l,detail sectional view of the piston of Figure et as seen at right angles thereto.

In the preferred form of the invention-as illustrated in the drawings I employ a sectional engine case comprising an upper crank case 1, an intermediate block 2 and a lower; crank case 3, which sections are detachably bolted 4or otherwise secured together to facilitate access to the several pistons and their connections.

A water jacket a is shown around the cylinder portion of the case between thek crank lcas'es for cooling purposes, and two crank shafts 5 and 6 are shown in Figure 1 journaled in parallel planes in their respective cases. Either of these shafts may beused 'to transmit power, but for conven-V ience I have shown the crank of shaft 5 as a cam shaft for operating the valves of the pistons' and shaft 6 as a driving or engine shaft with a balance or fly wheel 7 thereon. The'usual cooling fan 8 may be driven from a belt 9 and pulley 10 on the crank shaft in customary manner. Y

The two shafts 5 and 6 are geared to revolvo together through a drive gear 11 on the crank shaft Gand gear 12 on the crank shaft 5 and an intermediate idle gear 13 is inter-posedbetween these gears as indicated The gear 11 is one-half the diameter of the gear 12 giving a ratio of 2:1 to provide a two cycle operation of the cam shaft and upper part of the cylinders and a four lcycle operation of the crank shaft and lowerparts of the cylinders.

The four cylinders of the motor are designated 1415 16 and 17 reading from the left in Figure 1, and as. shown these cylinders are open at bottom and top and are formed of the three sections of the engine casing.

In each cylinder a pair of pistons are arpistons are designated 18 and 19,20 and 21. 22 and 23, and 24 and 25, in the respective cylinders and reading from left to rightin Figure l1. The lower pistons have connecting rods 26 journaledto the crank at 27. and theupper pistons have connecting rods 2S connected with the cam shaft 5. The connections with the cam shaft are offset quai'- `ters andthe connections of therods to the crank shaft are; offset at halves to insure rihe opposed loo propelI performance of the two cycles at the upper and lower portions of the engine.

The tour lower pistons are ot usual or standard construction. while the tour upperpistons complementary thereto are ot specific construction tor arrying out the principles ot my invention.

In Figures 4 and 5 the construction ot one o'l the Valve-pistons or upper pistons is illustrated. and as the other three are ot similar construction. a description ot one will sut'tice for all ot them.

As seen in Figures l and the hollow valve pistons are each fashioned with an exhaust port 2S) and an intake port l() lolated in opposite side walls of the piston and at ditterent transverse planes. The exhaust port adapted to register with a complementary exhaust port 3l in the cylinderand the intake port 230 is adapted to register with the intake. port irl ot the cylinder reeeiyine` the titel supply. Any standard torm ol carbureter may be connected with the intake manifold 3? in Figure 2 which communicates with the several intake ports ot' the e \tlinders. and the exhaust manifold 3ft is adapted to exhaust gases trom the seit'eral cylinders.

The intake port 2:30 to the piston opens to a luel supply chamber 35 in the piston and this chamber is fashioned with a valve seat 3G in the piston head tor the intake valve 3T.

An exhaust valve 38 adapted to seat in a port 39 in the piston head controls passage of gases of combustion to the exhaust chamber 4t) with which the exhaust port 2S) in the piston communicates.

llach ot the intake and exhaust valves has a stem as ll and l2 which project up iardly into the hollow wrist pin l?, of the piston and throne-h a sleeve slt 'tor the pin. Springs on the stems normally hold the valves closed in their seats in the piston head.

The valve operating1r mechanism includes a rod l-( vtor the intake and a valve rod LT for the exhaust. one at each side ot' the connecting rod These push rods are carried by the connectingr rod but are slidable relatively thereto and are supported in guide bosses t8 arranged in pairs at the sides ot the connecting rod.

llach push rod carries a cam wheel A.t9 at its outer end. and the crank ot the shatt 5 is provided with a pair ot' cams and 5l lor co-action with the wheels o'l the intake and exhaust push rods respectively. s seen in Figures 3. et. and the cam rodsor push rods meet and contact with the valve stents of the two ralvcs within the center ot' the hollow wrist pin, and the rods are intermittently actuated at the propel' times to push the valve stems to open the valves. This movement is actuated through the timing;- QCNS vtrom the drivingl shait't and through the crank shaft, cams thereon and the cam or push rods.

The fuel charge `tor comlgustion is admitted to the combustion chamber `tot-med between the opposingl pistons in the cylinder. through the valve seat when the intake Valve is opened by the cam action. A spark plut` 53 (Fig. 3) oi usual or lstandard torni is eniployed to ignite the tuel charge in the combustion chamber. The spark plug is preferably located above the median line ot the cylinder and toward the upper end thereot. and the tuel charge is compressed at a point between the two pistons when the lower piston is at the upper end oi its up .stroke and the valve piston on the halt stroke. as in Figure I, which shows the exhaust position in cylinder l? and the tiring position in cylinder l5.

In No. l cylinder at the le'lt shown in Figure l as l-.lboth the pistons are at: the end ot a stroke in the ends ot the cylinders and spaced at their extreme positions 'for the expanding' position. y

.its the engine is operated both pistons more toward each other. the tour cycle piston 1S) traveling twice as tast as the two cycle or lower piston 18. The piston 19 there'lore approacht-s piston 18 when the latter has made one halt its stroke during the time the piston 19 has made its full insti-oke, and the crank shaft G is on the dead center. This exhaust position is indicated in cylinder 15, in l `igure il, which is exhausted.

The piston 19 then mores on its outstroke making a tull reach oit its cylinder and piston '1S also reaches the end of the cylinder on its instroke. with the throw of both shatts pointing downwardly as in oylinder lt. During this outstroke ot' the piston 18 a luel charge has been drawn into the combustion chamber between the adjoining heads ot the pistons.

The compression stroke now takes place, both pistons startingl on an upstroke with the piston 18 movingI more rapidly than piston 19 to compress the fuel charge. When piston 18 has completed its niovement piston 19 has made only a halt stroke, the charge has been compressed and the pistons are in tiring;` position for ignition of the charge by the spark plug. The, combustion drives both pistons on an ont-stroke to expansion position ot cylinder 14 and the cycle is repeated.

In the exhaust position o't the pistons of ltigure 3 in cylinder 'l5 the exhaustI has taken place. 'alre 38 has closed and the exhaust port 29 of the piston is closed against port 3l in the cylinder wall. but intake valve 3T is about to open. The intake port 252 ot the piston is in line with port 3() in the cylinder wall and on the outward stroke lollo win g the two ports register while the valves remain closed, hence no action takes place through the ports.

The parts are so timed and arranged that compression and explosion take place when the crank pin 5 is at its full leverage, with its piston one haltI way on its outward stroke, and as the piston as 20 reaches nearly the end of its stroke the piston 21 is on the full leverage of the Crank pin 6.

The exhaust rvalve does not open against pressure of explosion when gas is :ted to the combustion chamber due to the fact that the expansion stroke is longer than the intake stroke. Little,.if any power :is used in soinpressing the mixture as the compressed mixture is forced against the pistonhead 20 at the full leverage of' the crank shaft by the piston 21 which at this time is near the end of its stroke with the crank shaft throw near the dead center. This force applied against piston 2O by the full leverage of the crank shaft assists in operating the upper pistons through the movement of the timing gears,

The crank pin G and its bearings are lubricated in usual manner, While the crank shaft and its parts are lubricated with oil :from the lower crank case through exterior oil pipe 54 in Figure 3 which communicates Withv the oil ducts in the cam shaft as indicated at 55 in Figure 17 and a pump 56 in the lower crank case is used to circulate the lubricant. Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

In a valved piston construction, a hollow wristV pin, a connecting rod connected thereover, said Wrist pin having guide slots formed therein at opposed points and in registry on opposite sides of said connecting rod, valve stems disposed through certain of the slots from the piston head, brackets projecting laterally from opposite sides of said connecting rod, 'push rods carried through said brackets for longitudinal movement relative to said connecting rod, Said push rods extendingthrough other of the wrist pin slots to engage said valve stems Within the Wrist pin, and means on said push rods for timed operative engagement with an engine crank shaft.

In testimony whereof I affix my signature.

FREDRICK IV. ITB-ESE. 

